Logging systems used for logging earth formations include wireline operated logging tools and wireless logging tools. Generally, wireless logging tools are battery powered and are provided with an electronic memory for storing the logging data. After conducting a logging run, the tool is retrieved to surface where the logging data are read out from the electronic memory.
A problem relating to the use of wireless logging tools is that during logging no information is available to the operator with regard to the functioning of the logging tool. For example, in case the logging tool is not correctly deployed in the borehole during the logging operation, the operator will notice the incorrect deployment only during read out of the electronic memory after one or more logging runs have been carried out. In such situation valuable drilling rig time is lost as it may be required to re-run the logging tool in the same wellbore interval. Also, circumstances may prevent rerunning of the logging tool in the same wellbore interval, leading to the absence of useful logging data for the interval.